The present invention relates to a hybrid transmission applicable to a hybrid vehicle using an engine and a motor/generator. More specifically, the present invention relates to a hybrid transmission which is capable of varying a transmission ratio continuously with a differential system connected between the engine and the motor/generator and which is applicable to a four wheel drive system.
A published Japanese patent application H11(1999)-332019 shows a hybrid system for driving the four wheels of a vehicle. This hybrid system have a hybrid transmission including a motor, and an additional motor provided for the wheels not driven by the hybrid transmission.